Resurrecting the Cornforth Model for Carbonyl Addition: Studies on the Origin of 1,2‐Asymmetric Induction in Enolate Additions to Heteroatom‐Substituted Aldehydes

Further experimental support for the Cornforth model is obtained from a systematic study of aldol reactions between methyl-substituted E and Z enolates and α-oxygen-substituted aldehydes. The observed dependence of diastereofacial selectivity on enolate configuration in this case is more consistent with the Cornforth model than with the the polar Felkin–Anh model (see scheme; X=OR, NR2, Cl).